The present invention relates to a vehicle seat, and more specifically, to a vehicle seat on which a child safety seat can be installed.
The present application claims priority from Japanese Patent Application No. 2002-319331, the disclosure of which is incorporated herein by reference.
Generally, an ISOFIX child safety seat involves the connection of a connector of a child safety seat to a fixation anchor attached to a vehicle body. As shown in FIG. 4A, since such a child safety seat simplifies its installation onto a vehicle seat and prevents erroneous attachment, the number of types of vehicle in compliance with the ISOFIX system tends to increase.
Another system, which is partially different from the above-described ISOFIX system, has also been proposed. According to such a system, instead of providing a fixation anchor at the side of the vehicle body, the fixation anchor is embedded in a rear end of a seat cushion as shown in FIG. 4B (for example, see pages 3 to 4 and FIGS. 1 to 3 of Japanese Patent Application Laid-Open No. 2001-122004).
In the former conventional system, as shown in FIG. 4A, in order to install a child safety seat 1 onto a vehicle seat 2, it is necessary to first insert a pair of connectors 6 (only one of them is shown) extending backwardly from a base seat 5 into a gap between a seat cushion 3 of the vehicle seat 2 and a seat back 4 while connecting the connectors 6 to fixation anchors 7 attached to a vehicle body so as to fix the base seat 5. However, since the fixation anchors 7 are provided in the rear of the seat back 4, the fixation anchors 7 are hard to see. Therefore, the alignment between the connectors 6 and the fixation anchor 7 needs the proficiency of a driver or a fellow passenger.
Therefore, without the proficiency in alignment, it is necessary to put a hand into the gap between the seat cushion 3 and the seat back 4 so as to confirm the positions of the fixation anchors 7 for installation of the child safety seat 1. Therefore, there is a possibility that the child safety seat 1 may not be installed as quickly as desired.
In addition, if a rear end of the seat cushion 3 of the vehicle seat 2 is formed so as to be upwardly raised, there will be a problem in that the connectors 6 may be caught by the rear end when the connectors 6 are to be inserted into the gap.
Moreover, the rear end of the seat cushion 3, which is upwardly raised, is integrally formed with a seat cushion pad 3A. Furthermore, a cushion wire 8 for keeping the shape of the seat cushion 3 is provided in the rear end of the seat cushion 3. Thus, it is difficult to form a concave portion and a guide hole in such a manner that the connectors 6 are not caught by the cushion wire 8 at the insertion of the connectors 6 in view of prevention of degradation in esthetic quality and the structure of a shape of the seat cushion pad 3A.
In order to solve the above-mentioned problems, the following method has been proposed. According to the method, a pair of hollow guide cups 9 as shown in FIG. 4C are inserted between the seat cushion 3 and the seat back 4 so as to be connected to the fixation anchors 7 in advance, thereby allowing an easy check of the positions of the fixation anchors 7. With such a method, although the workability at the installation of the child safety seat 1 can be improved, the appearance is not preferred when the child safety seat 1 is not installed. Moreover, each time an adult sits on the vehicle seat 2, the guide cups 9 should be detached.
According to the latter conventional method described in the above-mentioned patent document, since the fixation anchors 7 are provided in the gap between the seat cushion 3 and the seat back 4 as shown in FIG. 4B, the connectors 6 of the child safety seat 1 can be somewhat easily connected with the fixation anchors 7. However, a lower end of each of the fixation anchors 7 is connected to the rear end of a seat cushion frame 10 forming a framework structure of the seat cushion 3. Accordingly, the child safety seat 1 is directly connected and fixed to the seat cushion frame 10 via the fixation anchors 7.
Thus, a forward load, which is applied onto the child safety seat 1 when the child safety seat 1 is subjected to an impact, is entirely applied to the seat cushion frame 10. Therefore, not only a connected portion between the fixation anchor 7 and the seat cushion frame 10 but also the seat cushion frame 10 itself must be significantly reinforced in rigidity.